Busbar, motor, and power transmission system using same

ABSTRACT

Disclosed in one embodiment is a busbar comprising: an insulating body; a plurality of neutral terminals arranged in the insulating body; and a plurality of first driving terminals, second driving terminals, and third driving terminals arranged in the insulating body, wherein the plurality of neutral terminals, first driving terminals, second driving terminals, and third driving terminals are electrically insulated, respectively, and the shape of the plurality of the first driving terminals, the second driving terminals, and the third driving terminals are the same.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the continuation of U.S. application Ser. No.16/719,362, filed Dec. 18, 2019; which is the continuation of U.S.application Ser. No. 15/774,185, filed May 7, 2018, now U.S. Pat. No.10,547,228, issued Jan. 28, 2020; which is the U.S. national stageapplication of International Patent Application No. PCT/KR2016/012644,filed Nov. 4, 2016, which claims priority to Korean Application No.10-2015-0155177, filed Nov. 5, 2015, the disclosures of each of whichare incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present invention relates to a busbar, a motor, and a powertransmission system including the same.

BACKGROUND ART

Generally, an electronic power steering (EPS) system is a system forsecuring steering safety of a vehicle, and allows easy handling bysupplying power using a motor in a direction in which a driver steersthe vehicle.

Such an EPS system may improve a steering performance and a steeringfeeling by controlling an operation of the motor according to a drivingcondition unlike a conventional hydraulic power steering (HPS) system.

Specifically, the EPS system controls an inverter to drive the motoraccording to driving conditions detected by a vehicle speed sensor, atorque angle sensor, a torque sensor, and the like of an electroniccontrol unit (ECU). Accordingly, since a turning safety is secured and arapid restoring force is provided, the driver may safely drive.

Recently, safety requirements have been increased in the field ofvehicles. Accordingly, a technology in which a safety of a vehicle issecured even when some parts (ECU or inverter) of the EPS system are inimpossible operation states is required.

DISCLOSURE Technical Problem

The present invention is directed to providing a busbar with which aplurality of three-phase circuits may be formed.

The present invention is also directed to providing a motor having aplurality of three-phase circuits which are independently controlled.

The present invention is also directed to providing a power transmissionsystem in which a plurality of inverters control a motor.

Technical Solution

One aspect of the present invention provides a busbar including: aninsulating body; a plurality of neutral terminals disposed on theinsulating body; and a plurality of first driving terminals, seconddriving terminals, and third driving terminals disposed on theinsulating body, wherein the plurality of neutral terminals, firstdriving terminals, second driving terminals, and third driving terminalsare electrically insulated from each other, and the plurality of firstdriving terminals, second driving terminals, and third driving terminalshave the same shape.

The insulating body may include insertion grooves in which the pluralityof first driving terminals, second driving terminals, and third drivingterminals are disposed.

The plurality of neutral terminals may have the same shape.

The plurality of first driving terminals, second driving terminals, andthird driving terminals may be coplanar.

A radius of a curvature at one end of each of the plurality of firstdriving terminals, second driving terminals, and third driving terminalsmay be different from that of a curvature at the other end thereof.

The curvature of each of the plurality of first driving terminals,second driving terminals, and third driving terminals may be changedfrom the one end of each of the plurality of first driving terminals,second driving terminals, and third driving terminals toward the otherend thereof.

Each of the plurality of first driving terminals, second drivingterminals, and third driving terminals may include: a body portion; aconnection portion connected to the body portion; and a terminal portionprotruding from the body portion in a direction of a shaft.

The connection portion may include a first connection portion connectedto one end of the body portion, and a second connection portionconnected to the other end of the body portion.

The busbar may further include extension portions disposed between theconnection portion and the body portion, wherein the extension portionsmay extend in a direction perpendicular to the direction of the shaft,and a length of the extension portion connected to the first connectionportion may be different from that of the extension portion connected tothe second connection portion.

The length of the extension portion connected to the first connectionportion may be greater than that of the extension portion connected tothe second connection portion.

A curvature of the body portion may be changed from one end of the bodyportion toward the other end thereof.

Another aspect of the present invention provides a busbar including aninsulating body and a plurality of first, second, and third drivingterminals disposed on the insulating body, wherein a diameter of a firstvirtual circle connecting one ends of the plurality of first, second,and third driving terminals is less than that of a second virtual circleconnecting the other ends thereof.

The insulating body may include a first hole formed at a center of theinsulating body, and a diameter of the first hole may be less than thatof the first virtual circle.

Centers of the first hole, the first virtual circle, and the secondvirtual circle may be the same.

Still another aspect of the present invention provides a motor includinga stator including a first coil set and a second coil set, and a busbarincluding a first terminal set electrically connected to the first coilset to constitute a first circuit, a second terminal set electricallyconnected to the second coil set to constitute a second circuit, and aninsulating body configured to fix the first and second terminal sets,wherein each of the first terminal set and the second terminal setincludes at least one first driving terminal, at least one seconddriving terminal, and least one third driving terminal, and the firstdriving terminal, the second driving terminal, and the third drivingterminal have the same shape.

A curvature of each of the first driving terminal, the second drivingterminal, and the third driving terminal is changed from one end of eachof the first driving terminal, the second driving terminal, and thethird driving terminal toward the other end thereof.

Yet another aspect of the present invention provides a powertransmission system including: a motor including a first circuit and asecond circuit; a first driving unit electrically connected to the firstcircuit; a second driving unit electrically connected to the secondcircuit; and a control unit configured to control the first driving unitand the second driving unit, wherein the first circuit includes a firstcoil set and a first terminal set configured to electrically connect thefirst coil set, and the second circuit includes a second coil set and asecond terminal set configured to electrically connect the second coilset.

Advantageous Effects

According to embodiments, since a plurality of three-phase circuits canbe formed in a single motor, reliability can be improved.

Since shapes of terminals are the same, a manufacturing cost can bereduced.

Since the terminal is formed in a spiral shape, the plurality ofterminals can be densely disposed, and thus a size of the plurality ofterminals can be reduced.

Since a power terminal is separately manufactured, a manufacturingprocess can be simplified.

Since the terminals having the same shape are assembled, a structure ofan insulator can be simplified, and a productivity of an assemblyprocess can be improved.

Useful advantages and effects of the present invention are not limitedto the above-described contents, and may be more easily understood fromspecific embodiments of the present invention which will be described.

DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view illustrating a motor according to oneembodiment of the present invention.

FIG. 2 is a view for describing a state in which a busbar and a statoraccording to one embodiment of the present invention are electricallyconnected.

FIG. 3 is a view for describing a three-phase circuit of the motoraccording to one embodiment of the present invention.

FIG. 4 is a view illustrating a modified example of FIG. 3.

FIG. 5 is a view for describing an arrangement of a plurality of neutralterminals according to a circuit of FIG. 4.

FIG. 6 is a view for describing a shape of a driving terminal.

FIG. 7 is a view for describing an arrangement of a plurality of drivingterminals.

FIG. 8 is a plan view of FIG. 7.

FIG. 9 is a block diagram of a power transmission system according toone embodiment of the present invention.

FIG. 10 is a view illustrating a modified example of FIG. 9.

MODES OF THE INVENTION

While the present invention may be modified in various ways and take onvarious alternative forms, specific embodiments thereof are shown in theaccompanying drawings and described in detail below as examples.However, there is no intent to limit the present invention to theparticular forms disclosed. On the contrary, the present invention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the appended claims.

It should be understood that, although terms “first,” “second,” and thelike may be used herein to describe various elements, the elements arenot limited by the terms. The terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and similarly, a second element could be termed a firstelement without departing from the scope of the present invention. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

Terms used in the present specification are merely used to describeexemplary embodiments, and are not intended to limit the embodiments. Anexpression used in the singular encompasses the expression of theplural, unless it has a clearly different meaning in the context. In thepresent specification, it should be understood that the terms such as“including,” “having,” and “comprising” are intended to indicate theexistence of features, numbers, steps, actions, components, parts, orcombinations thereof disclosed in the specification, and are notintended to preclude the possibility that one or more other features,numbers, steps, actions, components, parts, or combinations thereof mayexist or be added.

In the description of embodiments, when an element is referred to asbeing “on or under” another element, the term “on or under” refers toeither a direct connection between two elements or an indirectconnection between two elements having one or more elements formedtherebetween. In addition, when the term “on or under” is used, it mayrefer to a downward direction as well as an upward direction withrespect to an element.

Hereinafter, embodiments will be illustrated in detail with reference tothe accompanying drawings, and components that are the same orcorrespond to each other regardless of reference numerals will bereferred to by the same or similar reference numerals, and redundantdescriptions thereof will be omitted.

FIG. 1 is a cross-sectional view illustrating a motor according to oneembodiment of the present invention.

Referring to FIG. 1, a motor 100 according to one embodiment of thepresent invention includes a housing 110, a stator 140 disposed in thehousing 110, a rotor 130, a rotating shaft 150, and a busbar 160.

The housing 110 may accommodate the stator 140 and the rotor 130. Thehousing 110 may further include a cooling structure (not shown) toeasily dissipate internal heat thereof. The cooling structure may be anair or water cooling structure, but is not limited thereto.

The stator 140 is inserted into an inner space of the housing 110. Thestator 140 may include a stator core 141 and coils 142 wound around thestator core 141. The stator core 141 may include a plurality of dividedcores. However, the stator core 141 is not limited thereto, and may alsobe integrally formed.

The rotor 130 may be disposed to rotate with respect to the stator 140.That is, the rotor 130 may rotate inside the stator 140. A rotor magnet132 may be installed on an outer circumferential surface of the rotor130.

The rotating shaft 150 may be coupled to a central portion of the rotor130. Accordingly, the rotor 130 and the rotating shaft 150 may rotatetogether. The rotating shaft 150 may be supported by a first bearing 171disposed at one side thereof and a second bearing 172 disposed at theother side thereof.

The busbar 160 may include a plurality of terminals electricallyconnected to the coils 142 wound around the stator 140 and configured toconnect a U-phase, a V-phase, and a W-phase. A power terminal 164 of thebusbar 160 may be exposed at the outside to be electrically connected toan external power or inverter.

FIG. 2 is a view for describing a state in which a busbar and a statoraccording to one embodiment of the present invention are electricallyconnected, FIG. 3 is a view for describing a three-phase circuit of themotor according to one embodiment of the present invention, FIG. 4 is aview illustrating a modified example of FIG. 3, and FIG. 5 is a view fordescribing an arrangement of a plurality of neutral terminals accordingto a circuit of FIG. 4.

Referring to FIG. 2, the stator 140 may include a plurality of dividedcores 141 a and a plurality of coils 142 wound around the divided cores141 a. The coil 142 may include one end 142 a and the other end 142 bwhich extend from the divided core 141 a in a direction of a shaft (alongitudinal direction of the rotating shaft). The one end 142 a may bea point from which coil winding starts, and the other end 142 b may be apoint at which the coil winding ends. However, the one end 142 a and theother end 142 b are not limited thereto. For example, the one end 142 amay be a position at which coil winding ends, and the other end 142 bmay be a position from which the coil winding starts.

The one end 142 a of each of the plurality of coils 142 may beelectrically connected to a neutral terminal 162, and the other end 142b may also be electrically connected to any one of driving terminals163.

The busbar 160 may include an insulating body 161, a plurality ofneutral terminals 162, and a plurality of driving terminals 163.

The insulating body 161 electrically insulates the plurality of neutralterminals 162 from the plurality of driving terminals 163. Theinsulating body 161 may include a plurality of insertion grooves 161 bin which the plurality of driving terminals 163 may be installed. Theneutral terminal 162 is integrally injected with the insulating body 161as example, but is not limited thereto. A material of the insulatingbody 161 is not specifically limited as long as the material has aninsulating property. For example, the insulating body 161 may be formedby injection-molding a plastic resin.

The plurality of insertion grooves 161 b may be formed to have apredetermined distance to electrically insulate the driving terminals163. A distance between the insertion grooves 161 b may be 0.5 mm to 2.0mm, but is not limited thereto. The plurality of insertion grooves 161 bmay have the same spiral shape. The insulating body 161 may have acircular plate shape in which a first hole 161 a is formed in a centerthereof, but is not limited thereto.

The neutral terminal 162 may serve to connect neutral points of theplurality of coils 142. Here, the neutral terminal 162 may include theplurality of neutral terminals 162 which are electrically insulated.Accordingly, the motor 100 may include a plurality of neutral points,and the plurality of neutral points may be electrically insulated.

The plurality of driving terminals 163 may be connected to a powerterminal 164. That is, the driving terminal 163 may be structurallyseparated from the power terminal 164. In such a structure, an invertermay be directly connected to an upper side of the busbar 160, and thestructure of the power terminal 164 may be suitably changed according toa structure of the motor. However, the structure of the power terminal164 is not limited thereto and may also be a power cable type. The powerterminal 164 may include a plurality of connection fins 164 belectrically connected to the plurality of driving terminals 163 and afixed part 164 a at which the connection fins 164 b are disposed.

The plurality of driving terminals 163 may serve to supply three-phasepower to the coil 142. A three-phase circuit may be formed byelectrically connecting the terminals of the busbar 160 and the coils142

The plurality of driving terminals 163 may include a plurality of firstdriving terminals UT1 and UT2, second driving terminals VT1 and VT2, andthird driving terminals WT1 and WT2. The first driving terminals UT1 andUT2 may be U-phase terminals, the second driving terminals VT1 and VT2may be V-phase terminals, and the third driving terminals WT1 and WT2may be W-phase terminals.

The U-phase terminals UT1 and UT2 may include a first U-phase terminalUT1 and a second U-phase terminal UT2, the V-phase terminals VT1 and VT2may include a first V-phase terminal VT1 and a second V-phase terminalVT2, and the W-phase terminals WT1 and WT2 may include a first W-phaseterminal WT1 and a second W-phase terminal WT2. In such a configuration,a plurality of three-phase circuits may be formed in the motor. However,the number of terminals is not limited.

Referring to FIGS. 3 and 4, the motor may include two independentthree-phase circuits. A first circuit may be formed by connecting thefirst U-phase terminal UT1, the first V-phase terminal VT1, and thefirst W-phase terminal WT1 to a plurality of coils U1, U3, V1, V3, W1,and W3.

The second circuit may be formed by connecting the second U-phaseterminal UT2, the second V-phase terminal VT2, and the second W-phaseterminal WT2 to a plurality of coils U2, U4, V2, V4, W2, and W4. Thefirst circuit may be an independent circuit connected by a first neutralpoint N1, and the second circuit may be an independent circuit connectedby a second neutral point N2.

Here, a set of coils constituting the first circuit may be defined as afirst coil set U1, U3, V1, V3, W1, and W3, and a set of coilsconstituting the second circuit is defined as a second coil set U2, U4,V2, V4, W2, and W4.

Referring to FIG. 4, a motor may also include four neutral points N1 toN4. A first circuit may include a first neutral point N1 and a secondneutral point N2, and a second circuit may include a third neutral pointN3 and a fourth neutral point N4. A three-phase circuit may also havemore neutral points as necessary.

Referring to FIG. 5, four neutral terminals 162 may be disposed toinclude four neutral points which are electrically insulated. Here, theneutral terminals 162 may have the same shape. Specifically, the neutralterminal may include a body portion 1621 having a curvature, anextension portion 1622 bent in the direction of the shaft, and aconnection portion 1623.

However, the neutral terminal is not limited thereto. Two neutralterminals 162 may also be disposed to include two neutral points asillustrated in FIG. 3, and shapes thereof may also be different.

FIG. 6 is a view for describing a shape of a driving terminal, FIG. 7 isa view for describing an arrangement of a plurality of drivingterminals, and FIG. 8 is a plan view of FIG. 7.

Referring to FIG. 6, each of the plurality of driving terminals 163 mayinclude a body portion 1631, a connection portion 1634 connected to thebody portion 1631, and a terminal portion 1635 protruding from the bodyportion 1631 in the direction of the shaft.

The body portion 1631 extends in a predetermined length to connect aplurality of connection portions 1634. The body portion 1631 may have astrip shape having a curvature. A radius of the curvature of the bodyportion 1631 may change from one end 1632 toward the other end 1633.

The body portion 1631 may have a spiral shape. Here, the spiral shapemay be defined as a shape in which a radius of a curvature changes fromthe one end 1632 toward the other end 1633. A radius of the curvaturemay increase from the one end 1632 toward the other end 1633. However,the radius of the curvature is not limited thereto, and may alsodecrease from the one end toward the other end. The radius of thecurvature at the one end 1632 is 20 mm, and a radius of the curvature atthe other end 1633 may be 30 mm, but the radii are not limited thereto.

As described above, the plurality of terminals configured to connectphases are disposed in the motor according to the embodiment asdescribed above. Accordingly, the number of terminals may increase totwo times that of a conventional motor. Such a spiral shape may beadvantageous for arranging the plurality of terminals in a limitedspace. A thickness of the body portion 1631 may range from 0.5 to 2.0mm, but is not limited thereto.

The connection portion 1634 is a portion electrically connected to thecoil. The connection portion 1634 may have a hook or Y shape, but is notlimited thereto. The connection portion 1634 may include a firstconnection portion 1634 a connected to the one end 1632 of the bodyportion 1631 and a second connection portion 1634 b connected to theother end 1633 of the body portion 1631. The number of connectionportions may be increased as necessary.

The terminal portion 1635 may protrude from the body portion 1631 in thedirection of the shaft. The terminal portion 1635 may be connected to anexternal power or an inverter to supply power to the connection portion1634.

An extension portion 1638 may be formed between the body portion 1631and the connection portion 1634.

The extension portion 1638 may include a first bent portion 1637protruding in the direction of the shaft and a second bent portion 1636extending from the first bent portion 1637 in a direction perpendicularto the shaft. A height of the connection portion 1634 may be determinedaccording to that of the first bent portion 1637. The terminal portion1635 may also be disposed on the extension portion 1638.

A length of the second bent portion 1636 connected to the firstconnection portion 1634 a may be longer than that of the second bentportion 1636 connected to the second connection portion 1634 b. Such astructure may expose the connection portion at the outside of theinsulating body to allow the connection portion to be electricallyconnected to the coil in a spiral type arrangement.

Referring to FIG. 7, all of the plurality of U-phase terminals UT1 andUT2, the V-phase terminals VT1 and VT2, and the W-phase terminals WT1and WT2 may have the same shape. In this case, since the terminals donot need to be separately manufactured, there is an effect in that amanufacturing cost is reduced, and there is an advantage in that anassembly is simplified.

All of the plurality of U-phase terminals UT1 and UT2, V-phase terminalsVT1 and VT2, and W-phase terminals WT1 and WT2 may be disposed to becoplanar. That is, the plurality of U-phase terminals UT1 and UT2,V-phase terminals VT1 and VT2, and W-phase terminals WT1 and WT2 may beconnected to the coils at the same height.

The first U-phase terminal UT1, the first V-phase terminal VT1, and thefirst W-phase terminal WT1 may be a first terminal set 163 aconstituting the first circuit, and the second U-phase terminal UT2, thesecond V-phase terminal VT2, and the second W-phase terminal WT2 may bea second terminal set 163 b constituting the second circuit.

Referring to FIG. 8, a diameter of a first virtual circle CL1 whichconnects the one ends 1632 of the first U-phase terminal UT1, the secondU-phase terminal UT2, the first V-phase terminal VT1, the second V-phaseterminal VT2, the first W-phase terminal WT1 and the second W-phaseterminal WT2 may be less than that of a second virtual circle CL2 whichconnects the other ends 1633 thereof. Accordingly, the first U-phaseterminal UT1, the second U-phase terminal UT2, the first V-phaseterminal VT1, the second V-phase terminal VT2, the first W-phaseterminal WT1 and the second W-phase terminal WT2 may be densely disposedin a limited space.

Here, a diameter of the first hole 161 a formed in the insulating bodymay be less than that of the first virtual circle CL1, and the firsthole 161 a, the first virtual circle CL1, and the second virtual circleCL2 may have the same center P. In addition, all angles θ betweenvirtual lines L1 to L6 from the center P to the one ends 1632 of theterminals may be the same.

FIG. 9 is a block diagram of a power transmission system according toone embodiment of the present invention, and FIG. 10 is a modifiedexample of FIG. 9.

Referring to FIG. 9, a power transmission system according to oneembodiment of the present invention includes a motor 100 having a firstcircuit 100 a and a second circuit 100 b, a first driving unit 30electrically connected to the first circuit 100 a, a second driving unit40 electrically connected to the second circuit 100 b, and a controlunit 10 configured to control the first driving unit 30 and the seconddriving unit 40.

The first circuit 100 a and the second circuit 100 b of the motor 100having the same configurations as described above may be included in thepower transmission system. The first circuit 100 a includes a first coilset and a first terminal set configured to electrically connect thefirst coil set, and the second circuit 100 b includes a second coil setand a second terminal set configured to electrically connect the secondcoil set.

The first terminal set may include a first U-phase terminal UT1, a firstV-phase terminal VT1, and a first W-phase terminal WT1, and the secondterminal set may include a second U-phase terminal UT2, a second V-phaseterminal VT2, and a second W-phase terminal WT2.

Each of the first driving unit 30 and the second driving unit 40 may bean inverter configured to convert direct current (DC) power suppliedfrom a power source 20 into three-phase power. The power source 20 maybe a vehicle battery.

The first driving unit 30 may be connected to U-phase, V-phase, andW-phase of the first circuit 100 a to supply three-phase power to thefirst circuit 100 a, and the second driving unit 40 may be connected toU-phase, V-phase, and W-phase of the second circuit 100 b to supplythree-phase power to the second circuit 100 b. That is, the firstdriving unit 30 and the second driving unit 40 may independently drivethe first circuit 100 a and the second circuit 100 b. Accordingly, evenin a case in which any one of the first driving unit 30 and the seconddriving unit 40 does not operate, the motor 100 may be operated by theremaining driving unit. Accordingly, the power transmission system maybe suitable for the field such as a vehicle demanding a high level ofsafety.

The control unit 10 may output a control signal to the first drivingunit 30 and the second driving unit 40 according to driving conditionsdetected by a vehicle speed sensor, torque angle sensor, torque sensor,and the like. The control unit 10 may be an electronic control unit(ECU). Referring to FIG. 10, the control unit 10 may include a firstcontrol unit 11 configured to control the first driving unit 30 and asecond control unit 12 configured to control the second driving unit 40.In this case, even in a case in which any one of the first control unit11 and the second control unit 12 does not operate, the motor may becontrolled by the remaining control unit.

1. A busbar comprising: an insulating body; a plurality of first drivingterminals disposed on the insulating body; a plurality of second drivingterminals disposed on the insulating body; a plurality of third drivingterminals disposed on the insulating body; and a neutral terminaldisposed on the insulating body, wherein a first end of the plurality ofthe first driving terminals, a first end of the plurality of the seconddriving terminals, and a first end of the plurality of the third drivingterminals are disposed on a first virtual circle, wherein a second endof the plurality of the first driving terminals, a second end of theplurality of the second driving terminals, and a second end of theplurality of the third driving terminals are disposed on a secondvirtual circle, wherein a diameter of the second virtual circle isgreater than a diameter of the first virtual circle, and wherein acenter of the first virtual circle is identical to a center of thesecond virtual circle.
 2. The busbar of claim 1, wherein the pluralityof first driving terminals, second driving terminals, and third drivingterminals have the same shape.
 3. The busbar of claim 1, wherein theplurality of the first driving terminals, the second driving terminals,and the third driving terminals comprise: a body portion comprising thefirst end and the second end; connection portions connected to the firstend of the body portion; and a terminal portion protruding from the bodyportion in a direction of a shaft.
 4. The busbar of claim 1, wherein theneutral terminal comprises a plurality of neutral terminals, and whereinshapes of the plurality of the neutral terminals are identical.
 5. Thebusbar of claim 1, wherein the insulating body includes insertiongrooves in which the plurality of the first driving terminals, thesecond driving terminals, and the third driving terminals are disposed.6. The busbar of claim 1, wherein the plurality of first drivingterminals, second driving terminals, and third driving terminals arecoplanar.
 7. The busbar of claim 3, wherein connection portions comprisea first connection portion connected to the first end of the bodyportion and a second connection portion connected to the second end ofthe body portion.
 8. The busbar of claim 7, comprising extensionportions disposed between the connection portion and the body portion,wherein the extension portions extend in a direction perpendicular tothe direction of the shaft; and wherein a length of the extensionportions connected to the first connection portion is different from alength of the extension portions connected to the second connectionportion.
 9. The busbar of claim 8, wherein the length of the extensionportions connected to the first connection portion is greater than thelength of the extension portions connected to the second connectionportion.
 10. A busbar comprising: an insulating body; a plurality offirst driving terminals disposed on the insulating body; a plurality ofsecond driving terminals disposed on the insulating body; a plurality ofthird driving terminals disposed on the insulating body; and a neutralterminal disposed on the insulating body, wherein the plurality of thefirst driving terminals, the second driving terminals, and the thirddriving terminals comprise: a body portion comprising a first end and asecond end; connection portions connected to the first end of the bodyportion; and a terminal portion protruding from the body portion in adirection of a shaft, wherein at least one of the plurality of the firstdriving terminals, at least one of the plurality of the second drivingterminals, and at least one of the plurality of the third drivingterminals has the same shape.
 11. A motor comprising: a housing; astator disposed in the housing; a rotor disposed in the housing; a shaftdisposed in the housing; and a busbar disposed on the stator, whereinthe busbar comprises: an insulating body; a plurality of first drivingterminals disposed on the insulating body; a plurality of second drivingterminals disposed on the insulating body; a plurality of third drivingterminals disposed on the insulating body; and a neutral terminaldisposed on the insulating body, wherein a first end of the plurality ofthe first driving terminals, a first end of the plurality of the seconddriving terminals, and a first end of the plurality of the third drivingterminals are disposed on a first virtual circle, wherein a second endof the plurality of the first driving terminals, a second end of theplurality of the second driving terminals, and a second end of theplurality of the third driving terminals are disposed on a secondvirtual circle, wherein a diameter of the second virtual circle isgreater than a diameter of the first virtual circle, wherein a center ofthe first virtual circle is identical to a center of the second virtualcircle.
 12. The motor of claim 11, wherein the plurality of firstdriving terminals, second driving terminals, and third driving terminalshave the same shape.
 13. The motor of claim 11, wherein the plurality ofthe first driving terminals, the second driving terminals, and the thirddriving terminals comprise: a body portion comprising the first end andthe second end; connection portions connected to the first end of thebody portion; and a terminal portion protruding from the body portion ina direction of a shaft.
 14. The motor of claim 11, wherein the neutralterminal comprises a plurality of neutral terminals, and wherein shapesof the plurality of the neutral terminals are identical.
 15. The motorof claim 11, wherein the insulating body includes insertion grooves inwhich the plurality of the first driving terminals, the second drivingterminals, and the third driving terminals are disposed.
 16. The motorof claim 11, wherein the plurality of first driving terminals, seconddriving terminals, and third driving terminals are coplanar.
 17. Themotor of claim 13, wherein connection portions comprise a firstconnection portion connected to the first end of the body portion and asecond connection portion connected to the second end of the bodyportion.
 18. The motor of claim 17, comprising extension portionsdisposed between the connection portion and the body portion, whereinthe extension portions extend in a direction perpendicular to thedirection of the shaft; and wherein a length of the extension portionsconnected to the first connection portion is different from a length ofthe extension portions connected to the second connection portion. 19.The motor of claim 18, wherein the length of the extension portionsconnected to the first connection portion is greater than the length ofthe extension portions connected to the second connection portion.
 20. Apower transmission system comprising: a motor including a first circuitand a second circuit; a first driving unit electrically connected to thefirst circuit; a second driving unit electrically connected to thesecond circuit; and a control unit configured to control the firstdriving unit and the second driving unit, wherein the first circuitincludes a first coil set and a first terminal set configured toelectrically connect the first coil set, and the second circuit includesa second coil set and a second terminal set configured to electricallyconnect the second coil set, wherein the first terminal set and thesecond terminal set comprise a plurality of first driving terminals, aplurality of second driving terminals, and a plurality of third drivingterminals, wherein a first end of the plurality of the first drivingterminals, a first end of the plurality of the second driving terminals,and a first end of the plurality of the third driving terminals aredisposed on a first virtual circle, wherein a second end of theplurality of the first driving terminals, a second end of the pluralityof the second driving terminals, and a second end of the plurality ofthe third driving terminals are disposed on a second virtual circle,wherein a diameter of the second virtual circle is greater than adiameter of the first virtual circle, and wherein a center of the firstvirtual circle is identical to a center of the second virtual circle.